RU2088329C1 - Method of producing the sorbent for hydrogen sulfide - Google Patents

Abstract

FIELD: chemical technology. SUBSTANCE: the main component of sorbent is the dispersed industrial waste containing 50-75% iron oxides, for example, hematite. Hematite is subjected for the combined grinding with activator-steam generator, for example, ammonium chloride at amount 5-15% of the main component weight and binding agent - sodium lignosulfate at amount 15-30% of the main component weight. Tablets or granules were made of the mixture that were subjected for thermic treatment in hydrogen atmosphere being firstly under polythermic conditions up to 500-650 C for 1 h and then - under isothermal conditions at 500-650 C for 60-90 min. EFFECT: improved method of producing. 3 cl, 1 tbl

Description

 The invention relates to chemical technology, mainly to methods for producing sorbents that can be used to purify industrial and natural gases, as well as ventilation air from hydrogen sulfide.

 In modern chemical technology, dry cleaning is used for a high degree of gas purification from hydrogen sulfide with a low hydrogen sulfide content (up to 0.5%). For this purpose, activated carbons or sorbents based on activated carbons and alumina impregnated with iodine are mainly used (GDR patent N 283275, class C 01 B 31/08, publ. 10.10.90).

 Known sorbents are difficult to manufacture and operate, expensive in cost and unsuitable for mass use.

A known method of producing tablets of a sorbent for hydrogen sulfide, comprising mixing its main component with a binder and activator-pore former (US patent N 4732888, CL B 01 J 20/02 publ. 22.08.88). As the main component, ZnO and Fe ₂ O ₃ powders with a particle size of about 1 μm in an amount ensuring the formation of zinc ferrite are used, and as a binder starch and / or methyl cellulose in an amount of ≅15% with an inorganic additive bentonite and / or kaolite and / or Portland cement in an amount of ≅5% and as an activator of Na ₂ CO ₃ in an amount of ≅5%, tablets are made from the resulting mixture and sintered at 1800 ^° C. to obtain a sorbent with a specific surface area of 0.5-5 m ² / g.

However, according to the existing method, the production of a sorbent for hydrogen sulfide is carried out at a high heat treatment temperature of the granules, which is necessary for the decomposition of the activator and pore former (Na ₂ CO ₃ - sodium carbonate, as well as the formation of zinc ferrite from iron and zinc oxides, in which the formation of the liquid phase of the binder, whereby the sorbents prepared in low specific surface area 0.5 m ² g 5, and hence a low sorptive capacity. in addition to manufacturing the sorbent as a major constituent ca. nyayut oxides of zinc and iron highly dispersed (about 1 micron), which are relatively expensive.

 The invention is aimed at reducing the temperature of the heat treatment of tablets or granules and achieving a higher specific surface area of the sorbent.

This is achieved by the fact that in the method for producing a sorbent for hydrogen sulfide, including mixing the main component of the sorbent with an activator-pore former and a binder, manufacturing tablets and their heat treatment, industrial waste containing 50-75% iron oxide, for example, red mud, is used as the main component , as a pore-forming activator, a substance is introduced in which a gaseous component is released at a temperature of 300-500 ^o C, for example ammonium chloride, in an amount of 5-15% by weight of the main component of the sorbent nt, as a binder, sodium lingosulfate is used in an amount of 15-30% by weight of the main component of the sorbent, they are subjected to mixing grinding until a homogeneous mass is formed from which tablets or granules are made, and they are heat treated in an atmosphere of hydrogen at a temperature of 500-650 ^o C first in polythermal and then in isothermal conditions. In this case, heat treatment under polythermal conditions is carried out within 60 minutes, and in isothermal conditions 60-90 minutes.

 The selected heat treatment conditions and the amount of activator-pore-forming agent and binder introduced ensure sequential release of physical and constitutional water, pyrolysis and evaporation, sublimation or decomposition of the activator and pore-forming agent, for example, sublimation of ammonium chloride, and reduction of iron oxides, which ensures the formation of a large number of open pores and sorbent production with a higher specific surface and sufficient strength.

Examples. The initial red mud was analyzed for iron oxide content and moisture. At a moisture content of more than 8%, the red mud was dried. In 1 00 g of red mud, 5-15% ammonium chloride, 15-30% sodium lingosulfate with a density of 1.25 g / cm ³ were introduced and subjected to mixing grinding in a ball mill for 5 hours, and then tablets and granules were made: tablets with a diameter of 2 mm, 2-5 mm long, granules + 1-5 mm.

Air-dry tablets or granules within 60 minutes. heated in polythermal conditions to 500-650 ^o C, and then in isothermal conditions at 500-650 ^o C kept for 60-90 minutes The atmosphere is hydrogen, its flow rate is 0.5 l / min. Tablets or granules cooled in a hydrogen atmosphere were packed into sealed containers. The specific surface was measured by the BET method by nitrogen adsorption at the temperature of liquid nitrogen (see table).

Using the proposed method, obtaining a sorbent for hydrogen sulfide provides the following advantages compared to existing methods:
the possibility of obtaining sorbents from cheaper secondary raw materials, dispersed industrial waste, thereby comprehensively address environmental protection;
reduction of energy consumption during heat treatment of tablets or granules of the sorbent by lowering the temperature of heat treatment;
obtaining sorbents with a higher specific surface, and therefore sorption capacity, which will significantly reduce the cost of sorbents.

Claims (3)

1. A method of producing a sorbent for hydrogen sulfide, comprising mixing the main component of the sorbent with an activator-blowing agent and a binder, the manufacture of tablets and their heat treatment, characterized in that the main component is industrial waste red mud containing 50 75% iron oxide, as an activator -poreforming agent is introduced a substance in which a gaseous component is released at 300 500 ^o C in an amount of 5-15% by weight of the main component of the sorbent, sodium lignosulfate is used as a binder In an amount of 15-30% of the mass of the main component of the sorbent, they are subjected to mixing milling until a homogeneous mass is formed from which tablets or granules are made, and they are heat-treated in an atmosphere of hydrogen at 500 650 ^o С, first under polythermal and then under isothermal conditions .  2. The method according to claim 1, characterized in that the heat treatment in polythermal conditions is within 60 minutes, and in isothermal conditions 60 to 90 minutes  3. The method according to claim 1, characterized in that as the activator-pore former use ammonium chloride.

Images